Herpes simplex virus (HSV) causes infections characterized by inflammation of skin and mucosal membranes of the mouth and genital areas. The type of HSV most commonly associated with lesions of the mouth and facial region is Type 1 HSV. Type 2 HSV is most commonly associated with lesions of the genital region.
The symptoms of HSV generally include erythema, inflammation, pain, and lesions. Symptoms initially include tingling, pain, and/or swelling at the site of infection, followed by lesion formation (papules and vesicles) with scar formation and healing occuring in approximately ten to fourteen days. After the initial infection, recurrent attacks may occur throughout life in response to various stimuli, including changes in body temperature, stress, ultraviolet radiation and exposure to chemicals.
Treatments for HSV infections are limited in efficacy. There is no known cure at this time, although various anti-viral compositions are being marketed with claims of beneficial effects. Most anti-viral compounds currently in use are synthetic nucleoside analogs which interfere with the replication of viral DNA or RNA. The mode of action of these compounds is to directly interfere with the action of DNA or RNA polymerase or chain termination after incorporation into specific nucleic acid polymers.
Many synthetic nucleoside analogs have been tested for the ability to inhibit viral replication. However, most of these have unacceptable toxicity and cannot be used for treating humans. Interestingly, many useful nucleoside analogs have principal activity against the herpes group of viruses which include varicella-zoster virus, herpes simplex virus, Epstein Barr virus and cytomegalovirus.
Currently, there is only one commercially available FDA approved nucleoside analog which has been shown to be efficacious in the treatment of lesions of the skin produced by herpes simplex virus. This compound is produced by Burroughs Wellcome Company and has been given the name Acyclovir. Acyclovir has been shown to be effective in the treatment of primary genital herpes and, in many individuals, can reduce or prevent prevent recurrences when taken on a daily basis over long periods of time. Acyclovir (acycloguanosine) is administered systemically for treatment of HSV with some success. Topical acyclovir has been found to be somewhat effective for the primary lesion but not for recurrent lesions. There is a wealth of clinical and scientific literature relating to the use of acyclovir in herpes infection.
Interferon has also been tested systemically and topically against HSV but with only limited efficacy. There are so many side effects associated with systemic administration of anti-virals that topical treatments are greatly preferred. Unfortunately, the topical administration even of the compounds having some efficacy when administered systemically is generally ineffective.
It is therefore an object of the present invention to provide topical compositions and methods of use thereof for the alleviation of the symptoms associated with herpes simplex infections or other viral lesions.
It is a further object of the present invention to provide topical compositions for alleviation of the symptoms of HSV infection with minimal side effects and relief from inflammation and pain normally associated with vital lesions.